Correlation Between PAH Exposure In Indoor Environment And DNA Oxidation Damage In General Population,Guangzhou,South China

As one group of the classical semi-votile organic compounds?SVOCs?,polycyclic aromatic hydrocarbons?PAHs?in indoor environment and the related human exposure are demonstrated to have potential which could not be ignored.Now abundant biomonitoring evidences have shown the significant dose-response relationships between concentration levels of urinary PAH metabolites and biomarkers of oxidative stress,and the results were not comprehensively enough to figure out the profiles of potential exposure sources.Therefore,we selected the indoor environment as research object to analyze the potential relations among indoor contaminants?PAHs?,environmental oxidative potentian?OP?and the biomarker of human oxidative damage.In 2008,a total of 100 families were randomly recruited in Guangzhou,South China.Sixteen parent PAHs were measured in indoor dust and air samples,and selected PAH metabolites and DNA oxidative damage biomarker 8-hydroxy-2'-deoxyguanosine?8-OHd G?were also measured in 205 urine samples of total residents.Dusty OP was quantified by dithiothreitol?DTT?assay to study the correlations among environmental OP,indoor PAHs and biomarker of DNA oxidative damage.The average concentrations of?₁₆PAH in dust,particulate and gas were 5.22±22.3?g/g,2.71±2.86 ng/m³ and 77.8±61.1 ng/m³,respectively.Detection frequencies of most PAHs in dust and air were higher than 80%and 68%.We took family as a unit and adopted“environment”to“human”conresponding method to evaluate the estimated daily intakes?EDIs?of PAHs via four external exposure routes.Gas dermal contact was the main pathway for PAHs entering human body,followed by air inhalation,dust dermal contact and dust ingestion.The average corresponding EDIs were displayed as orders:77.0>19.5>3.75>1.60 ng/kg?bw/day and cumulative exposure level roughly up to 100 ng/kg?bw/day from indoor environment.The dietary rate contributed 62-99%of total exposure for NAP,FLU,PHE and PYR.The concentration of total hydroxyl PAHs??₈OH-PAH?in all urine samples was 0.29-78.6ng/m L?median:3.61 ng/m L,mean:6.74 ng/m L?.The concentration range of urinary 8-OHd G was 0.77-32.0 ng/m L?median:6.83 ng/m L,mean:3.58 ng/m L?.Liner regression analysis showed that the dose-response relationship between concentrations of OH-PAHs and 8-OHd G in male residents was stronger than that in female residents.For example,the regression coefficient of male's?₈OH-PAHs and 8-OHd G was 0.357?95%CI:0.237-0.477,p<0.001?which inditacted each 100%increase in the level of?8OH-PAH was accompanied by a 0.357%increase in the concentration of 8-OHd G in males,greater than that of female's 0.280%?95%CI:0.121-0.439,p=0.001?.This result indicated that the male residents were more likely susceptible to the DNA oxidative damage caused by PAH exposure.In addition,the results of DTT assay showed that the detective values of dusty OP ranged from 2.90 to 58.2 pmol/?min·?g?with an average value of 7.81±6.60 pmol/?min·?g?.No significant dose-relationship was observed between dusty OP and DNA oxidative damage biomarker 8-OHd G.This may be due to the low OP value in dust samples.Present study suggested a relationship between environmental OP and studied pollutants that PAHs in dust could gradually intensify the OP of dust particles with increases in molecular weight,with high-molecular-weight PAHs as the main congeners of OP in environmental matrix coused by individual PAHs.Further studies should improve the analysis of oxidative potential for various environmental samples,so as to comprehensively analyze the relationship between the pollutants exposure from external environment and human oxidative stress.